A fluorine-containing polymer made from a fluorine-containing alcohol monomer, in the field of producing semiconductors, can be used for, for example, topcoat of immersion lithography for its superior solubility in the developing solution (tetramethylammonium hydroxide, hereinafter it may be abbreviated as TMAH). A topcoat is a protective film to protect a resist film from chemical substances such as amines in the environment where lithography is conducted. A topcoat composition solution must be applied without attacking the resist film, and also be soluble in the alkali developing solution such as TMAH.
Patent Publication 1 states that a polymer which contains a fluorine-containing monomer represented by formula [1]
as its component is useful as a raw material of a removable temporary fixing adhesive for its low surface energy.
Furthermore, Patent Publication 2 states that, in a process of producing semiconductors, a polymer produced by using a fluorine-containing monomer represented by the formula [1] as a component, is useful as a topcoat for immersion lithography because its solubility in a developing solution is superior.
Patent Publication 3 states a method for synthesizing a fluorine-containing propanediol represented by formula [2].

Patent Publication 3 states a method (see the following reaction formula)

in which 1,1,1,3,3,3-hexafluoroacetone and cesium fluoride are stirred at −78° C., then acetaldehyde is added at room temperature to obtain 4,4,4-trifluoro-3-hydroxy-3-trifluoromethylbutylaldehyde as a fluorine-containing hydroxyaldehyde, and then lithium aluminum hydride is added to conduct a reduction, thereby obtaining 4,4,4-trifluoro-3-hydroxy-3-trifluoromethylbutanol, which belongs to a fluorine-containing propanediol represented by the general formula (2).
Patent Publication 4 discloses a method to gain 4,4,4-trifluoro-3-hydroxy-3-trifluoromethylbutanol (see the following reaction formula)
by reducing 4,4,4-trifluoro-3-hydroxy-3-trifluoromethylbutylaldehyde by a contact with hydrogen under a palladium catalyst.
As a method to synthesize 4,4,4-trifluoro-3-hydroxy-3-trifluoromethylbutylaldehyde, Patent Publication 5 states a method in which 1,1,1,3,3,3-hexafluoromethylbutylacetone and n-butyl vinyl ether are reacted to gain 4-butoxy-2,2-bistrifluoromethyloxetane, and then it is hydrolyzed in the presence of acid to gain that (see the following reaction formula).

However, the method stated in Patent Publication 3 or 4 has had a problem that it is difficult to pursue it in industrial scale, because of a low selectivity when gaining 4,4,4-trifluoro-3-hydroxy-3-trifluoromethylbutylaldehyde which is a fluorine-containing aldehyde, and therefore yield of 4,4,4-trifluoro-3-hydroxy-3-trifluoromethylbutanol, which is a derivative thereof, is as low as 50%.
Furthermore, there has been a problem that yield of 4,4,4-trifluoro-3-hydroxy-3-trifluoromethylbutylaldehyde, which is an object of the method stated in a Patent Publication 5, is as low as 47%.
Patent Publication 6 discloses a method of producing a diol by a cross aldol reaction of hexafluoroacetone and a carbonyl compound under an acid condition.